Monitoring Physiological Condition and Detecting Abnormalities

ABSTRACT

A system for monitoring an individual&#39;s physiological condition and detecting abnormalities therein, comprising concurrently receiving at least first signal and a second signal. The first and second signals are conditioned to minimize background extraneous noise after which, each signal is concurrently processed and analyzed to detect repeating cyclical patterns and further characterized to identify individual components of the repeating cycles. At least one individual component in one signal is selected as a reference marker for a selected component in the other signal. The two signals are then synchronized, outputs produced therefrom and stored in a database. The system is provided with a plurality of devices for acquiring, transmitting and conditioning at least two physiological signals, a software program cooperable with a microprocessor configured for receiving said transmitted signals and conditioned signals, and processing said signals to characterize and synchronize said signals and provide signal outputs derived therefrom, a database for storing said transmitted signals, conditioned signals, synchronized signals, and output signals derived therefrom. The output signals are useful for reporting and optionally for retransmission to the individual&#39;s body and providing physiologically stimulatory signals thereto.

FIELD OF THE INVENTION

This invention relates to monitoring cardiovascular health. Moreparticularly, this invention relates to systems and methods for earlydetection of cardiovascular abnormalities and malfunctions.

BACKGROUND OF THE INVENTION

Numerous types of malfunctions and abnormalities that commonly occur inthe cardiovascular system, if not diagnosed and appropriately treated orremedied, will progressively decrease the body's ability to supplysufficient oxygen to satisfy the coronary oxygen demand when theindividual encounters stress. The progressive decline in thecardiovascular system's ability to supply oxygen under stress conditionswill ultimately culminate in a heart attack, i.e., myocardial infarctionevent that is caused by the interruption of blood flow through the heartresulting in oxygen starvation of the heart muscle tissue (i.e.,myocardium). In serious cases, the consequences are mortality while inless serious cases, permanent damage will occur to the cells comprisingthe myocardiurn that will subsequently predispose the individual'ssusceptibility to additional myocardial infarction events.

In addition to potential malfunctions and abnormalities associated withthe heart muscle and valve tissues (e.g., hypertrophy), the decreasedsupply of blood flow and oxygen supply to the heart are often secondarysymptoms of debilitation and/or deterioration of the blood flow andsupply system caused by physical and biochemical stresses. While some ofthese stresses are unavoidable, e.g., increasing age, heredity andgender, many of the causative factors of cardiovascular diseases andmalfunction are manageable, modifiable and treatable if theirdebilitating effects on the cardiovascular system are detected earlyenough. Examples of such modifiable risk factors include high bloodpressure, management of blood cholesterol levels, Diabetes mellitus,physical inactivity, obesity, stress, and smoking. Examples ofcardiovascular diseases that are directly affected by these types ofstresses include atherosclerosis, coronary artery disease, peripheralvascular disease and peripheral artery disease. In many patients, thefirst symptom of ischemic heart disease (IHD) is myocardial infarctionor sudden death, with no precedin chest pain as a warning.

Screening tests are of particular importance for patients with riskfactors for IHD. The most common initial screening test for IHD is tomeasure the electrical activity over a period of time which isreproduced as a repeating wave pattern, commonly referred to as anelectrocardiograph (ECG), showing the rhythmic depolarization andrepolarization of the heart muscles. Analysis of the various waves andnormal vectors of depolarization and repolarization yields importantdiagnostic information. However, ECG measurements are not particularlysensitive nor are the data very useful for detecting cardiovascularabnormalities or malfunctions. Therefore, stressing the heart undercontrolled conditions and measuring changes in the ECG data is usually,but not always, the next step. The stresses may be applied by theperformance of physical exercise or alternatively, by administration ofpharmaceutical compounds such as dobutamine, which mimic thephysiological effects of exercise. Other screening tests for IHD includethe radionucleotide stress test which involves injecting a radioactiveisotope (typically thallium or canliolyte) into a patient's bloodstream,then visualizing the spreading of the radionucleotide throughout thevascular system and its absorption into the heart musculature. Thepatient then undergoes a period of physical exercise after which, theimaging is repeated to visualize changes in distribution of theradionucleotide throughout the vascular system and the heart. Stressechocardiography involves ultrasound visualization of the heart before,during and after physical exercise. The radionucleotide stress test andstress echocardiography arc often used in combination with ECGmeasurements in order to gain a clearer understanding of the state ofindividual's cardiovascular health.

However, there are a number of serious limitations associated with theuse of ECG and related stress tests for detecting abnormalities andmalfunctions that are indicators of isehemic heart disease. ECGprintouts provide a static record of a patient's cardiovascular functionat the time the testing was done, and may not reflect severe underlyingheart problems at a time when the patient is not having any symptoms.The most common example or this is in a patient with a history ofintermittent chest pain due to severe underlying coronary arterydisease. This patient may have an entirely normal ECG at a time when heis not experiencing any symptoms despite the presence of an underlyingcardiac condition that normally would be reflected in the ECG. In suchinstances, the ECG as recorded during an exercise stress test may or maynot reflect an underlying abnormality while the ECG taken at rest may benormal. Furthermore, many abnormal patterns on an ECG may benon-specific, meaning that they may he observed with a variety ofdifferent conditions. They may even be a normal variant and not reflectany abnormality at all. Routine exercise ECG is not recommended inpatients who have no signs or symptoms of coronary artery disease.Exercise ECG is notoriously ineffective at predicting underlyingcoronary artery disease, and a positive exercise ECG test in anapparently healthy patient is not known to have any association withcardiovascular morbidity and mortality.

Ballistocardiography (BCG) is a non-invasive method of graphicallyrecording minute movements on an individual's body surface as aconsequence of the ballistic i.e., seismic forces associated withcardiac function, e.g., myocardial contractions and related subsequentejections of blood, ventricular filling, acceleration, and decelerationof blood. flow through the great vessels. These minute movements areamplified and translated by a pick-up device (e.g., an accelerometer)placed onto a patient's sternum, into signals with electrical potentialsin the 1-20 Hz frequency range and recorded on moving chart paper. Therhythmic contractions of the heart and related flows of blood within andfrom the heart's chambers under resting and stressed conditions producerepeating BCG wave patterns that enable visual detection and assessmentby qualified diagnosticians of normal and abnormal cardiovascularfunction. The BCG records the vigor of cardiac ejection and the speed ofdiastolic filling. It provides a practical means of studying thephysiologic response of the heart in its adjustment to the stress ofexercise. The application of the light BCG exercise test to subjectswithout clinical or ECG evidence of heart disease, or to hypertensivesubjects, or to patients with coronary artery disease and to thosesuspected of having myocarditis, provides information of importancewhich cannot be obtained from any other means of physical diagnosis orfrom the BCG at rest (Mandelbaum et al., 1954. Circulation 9:388-399).The most common BCG wave pattern classification system is known as theStarr system (Starr et al., 1961, Circulation 23: 714-732) andidentifies four categories of cardiovascular function depending on theabnormalities in the measured BCG signals. In class 1, all BCG complexesare normal in contour. In class 2, the majority of the complexes arenormal, but one or two of the smaller complexes of each respiratorycycle are abnormal in contour. In class 3, the majority of the complexesare abnormal in contour, usually only a few of the largest complexes ofeach respiratory cycle remaining normal and in class 4, there is suchcomplete distortion that the waves cannot be identified with confidence,and the onset of ejection could not be located without the assistance ofa simultaneous ECG (Starr, 1964, J. Am. Med. Assoc. 187:511). Ingeneral, a normal healthy person should belong to Starr class 1, andperson belonging to class 3 or 4 has a significant abnormality in one ormore components of the cardiovascular system. However, theclassification is not exact, as it is done visually and depends on theperson making the classification (Starr, 1964, J. Am. Med. Assoc.187:511).

Coronary angiography enables visualization and assessment of potentialcardiovascular abnormalities and malfunctions that are not possible todetect with the afore-mentioned stress tests, including as occlusions,stenosis, restenosis, thrombosis, aneurismal enlargement of coronaryartery lumens, heart chamber size, heart muscle contraction performanceand heart valve function. During a coronary angiogram, a small catheteris inserted through the skin into an artery in either the groin or thearm. Guided with the assistance of a fluoroscope, the catheter is thenadvanced to the opening of the coronary arteries, the blood vesselssupplying blood to the heart. Next, a small amount of radiographiccontrast solution is injected into each coronary artery. The images thatarc produced are called the angiogram. Although angiographic imagesaccurately reveal the extent and severity of all coronary arterialblockages and details of the heart musculature, the procedure isinvasive and requires the use of local anaesthesia and intravenoussedation.

SUMMARY OF THE INVENTION

The exemplary embodiments of the present invention, at least in someforms, provide systems, methods, devices, apparatus and softwareprograms for acquiring, processing, synchronizing, storing and reportingat least two physiologically generated signals useful for monitoring thephysiological condition of a mammalian system and for detectingabnormalities therein.

According to one exemplary embodiment, there is provided a systemconfigured for monitoring the cardiovascular condition of a mammalianbody. The system is provided with at least: (a) a plurality of devicesconfigured to concurrently detect, acquire and transmit at least twodifferent types of physiological signals produced by the cardiovascularsystem, (b) an analog-digital converter for converting the signals intodigital data that can be processed and stored, (c) at least oneapparatus configured to receive therethrough and condition the at leasttwo signals, (d) a microprocessor suitably configured with hardware, anoperating system and software provided for concurrently processing,analyzing, characterizing, reporting and transmitting said physiologicaland said conditioned signals, (e) a software program configured toconcurrently process said conditioned signals to at least firstly detectrepeating cyclical patterns in the conditioned signals, secondly toidentify and characterize individual components comprising the repeatingcycles, thirdly to identify a first reference component in at a firstconditioned signal and a second reference signal in a second conditionedsignal, fourthly to synchronize at least a first conditioned signal witha second conditioned signal by aligning the first and second referencepoints, and then subsequently aligning the repeating cyclical pattern ofthe first conditioned signal with the repeating cyclical pattern of thesecond conditioned signal in constant reference to the first and secondreference points, and fifthly producing at least a synchronized pairedsignal derived therefrom, and (f) a database provided for communicatingand cooperating with the microprocessor for storing therein andproviding therefrom the physiological signals, conditioned signals,synchronized signals and signal outputs derived therefrom.

According to one aspect, there is provided a plurality of devicesconfigured for concurrently detecting, acquiring and transmitting atleast two physiological signals from a cardiovascular system. Exemplarysuitable signals include electrical signals, electronic signals, seismicsignals, mechanical signals, acoustic signals, imaging signals and thelike, Suitable devices are exemplified by electrocardiographs,ballistocardiographs, seismocardiographs, angiographs and the like.Additional physiological monitoring equipment and instrumentsexemplified by pulsoximeters and blood pressure measuring devices, maybe optionally provided to cooperate with said devices. The signals maybe transmitted by wires or by wireless means.

According to another aspect, there is provided a filtering apparatusconfigured to remove extraneous noise components from the digitalsignals converted from the physiological signals acquired from themammalian cardiovascular system thereby providing at least twoconditioned signals.

According to exemplary embodiment of the present invention, there isprovided at least one software program configured to concurrentlyperform a plurality of the following functions on the at least twoconditioned signals: (a) process, (b) analyze, (c) optimize, (d)transform, (e) identify repeating cyclical patterns, (f) identify andcharacterize individual components of the the repeating cyclicalpatterns, (g) identify a reference component in each of the cyclicalpatterns comprising each of the conditioned signals, (h) synchronize atleast two of the conditioned signals by aligning the reference componentof a first conditioned signal with the reference component of the secondconditioned signal, (i) generate output comprising at least onesynchronized signal wave pattern, (j) report identifying andcharacterizing key components of the at least one synchronized signalwave pattern relating to a physiological condition, (k) store, and (k)re-transmit the synchronized signals. It is within the scope of thisinvention for the synchronized signals to be transmitted back to themammalian system for providing a stimulatory signal thereto.

According to one aspect, the software program is suitably configured forprocessing, comparing and reporting a plurality of synchronized signals,and providing outputs therefrom.

According to another aspect, the software program may comprise aplurality of mathematical algorithms, or alternatively heuristicalgorithms, or optionally, a combination of mathematical and heuristicalgorithms.

According to another exemplary embodiment of the present invention,there is provided a database for storing therein and providing therefroma plurality of synchronized signals produced as disclosed herein.

According to one aspect, the database may be provided as an integralcomponent of the microprocessor provided herein.

According to another aspect, the database may be contained in a facilityprovided for such purposes. The database is configured receive thereinpluralities of synchronized signals produced as disclosed herein. Thesynchronized signals may be delivered to and transmitted from thedatabase base electrically, electronically, acoustically, via beams oflight, and the like using wired or alternatively wireless transmissionmethods.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in conjunction with reference tothe following drawing, in which:

FIG. 1 is a cross-sectional perspective view of the heart showing thetricuspid and mitral valves in opened positions, and the pulmonary andaortic valves in closed positions;

FIG. 2 is a cross-sectional perspective view of the heart showing thetricuspid and mitral valves in closed positions, and the pulmonary andaortic valves in opened positions;

FIG. 3 is a schematic diagram showing the relationships between therhythmic electrical functions and related physical motions of aphysiologically normal heart cooperating with a physiologically normalcardiovascular system, with reference to: (a) electrocardiographic (ECG)events, (b) systolic and diastolic periods of time, (c) blood pressureduring the systole and diastole periods, and (d) ballistocardiographic(BCG) events;

FIG. 4 is an exemplary chart showing the traditional Starr BCG signalclassification system;

FIG. 5 is a schematic diagram showing an exemplary system of the presentinvention configured for concurrently detecting and transmitting ECG andBCG signals produced by a heart to a device configured to synchronizeone of the signals and provide a visual output of the synchronized ECGand BCG signals;

FIG. 6 is an flow chart of one embodiment of the present inventionshowing an exemplary method for processing and synchronizingconcurrently produced ECG and BCG signals;

FIG. 7 is a graph illustrating a prior art curve-length concept;

FIG. 8 is a systems flow chart showing the data flow into and out of thegraphical user interface;

FIG. 9 is an exemplary illustration of a layout for an ECG-BCG analysisGraphical User Interface (GUI) according to one aspect of the presentinvention;

FIG. 10 is an exemplary illustration of a basic layout for a databaseaccording to one aspect of the present invention;

FIG. 11 is an exemplary illustration of a sample SQL data tableaccording to one aspect of the present invention;

FIG. 12 a shows a raw unconditioned and unsynchronized ECG-BCG signalset of a healthy individual with a well-functioning cardiovascularsystem, collected during a resting stage prior to exercising, while FIG.12 b shows a raw unconditioned and unsynchronized ECG-BCG signal setcollected from the healthy individual during the post-exercise period.

FIG. 13 a shows the resting stage ECG-BCG signal set from FIG. 12 aafter conditioning and synchronization according to one aspect of thepresent invention, FIG. 13 b shows the post-exercise ECG-BCG signal setfrom FIG. 12 b after conditioning and synchronization, and FIG. 13 cshows the synchronized post-exercise BCG signal overlaid onto thesynchronized pre-exercise resting-stage BCG signal;

FIG. 14 a shows a raw unconditioned and unsynchronized ECG-BCG signalset of an unhealthy individual with a somewhat debilitatedcardiovascular system, collected during a resting stage of prior toexercising, while FIG. 14 b shows a raw unconditioned and unsynchronizedECG-BCG signal set collected from the unhealthy individual during thepost-exercise period.

FIG. 15 a shows the resting stage ECG-BCG signal set from FIG. 14 aafter conditioning and synchronization according to one aspect of thepresent invention, FIG. 15 b shows the post-exercise ECG-BCG signal setfrom FIG. 14 b after conditioning and synchronization, and FIG. 15 cshows the synchronized post-exercise BCG signal overlaid onto thesynchronized pre-exercise resting-stage BCG signal;

FIG. 16 a shows a raw unconditioned and unsynchronized ECG-BCG signalset of an at-risk individual with a seriously debilitated cardiovascularsystem, collected during a resting stage prior to exercising, while FIG.16 b shows a raw unconditioned and unsynchronized ECG-BCG signal setcollected from the at-risk individual during the post-exercise period;

FIG. 17 a shows the resting stage ECG-BCG signal set from FIG. 16 aafter conditioning and synchronization according to one aspect of thepresent invention, FIG. 17 b shows the post-exercise ECG-BCG signal setfrom FIG. 16 b after conditioning and. synchronization, and FIG. 17 cshows the synchronized post-exercise. BCG signal overlaid onto thesynchronized pre-exercise resting-stage BCG signal; and

FIGS. 18 a, 18 b and 18 c are comparisons of the overlaid synchronizedpre- and post-exercise BCG signals for the healthy individual, unhealthyindividual, and at-risk individual respectively.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to the detection and monitoring of twodisparate signals associated with rhythmic electrical cardiovascularfunctions and physical movements associated with the beating of anindividual's heart, and the synchronization of a selected signal to theother signal whereby the synchronized signal enables and facilitatesdetection of potential abnormalities and malfunctions associated withthe individual's cardiovascular system. Two exemplary suitable signalsfor monitoring cardiovascular function and for synchronization with eachother are ECG and BCG signals. A brief description follows ofcardiovascular functions as they relate to the generation of ECG and BCGsignals, for reference to during disclosure herein of how either ofthese signals may be synchronized to the other for the detection ofpotential cardiovascular abnormalities and malfunctions according to thepresent invention.

As shown in FIGS. 1 and 2, the heart 10 comprises four chambers, theright atrium 20 interconnected with the right ventrical 30 by thetriscuspid valve 35, and the left atrium 40 interconnected with the leftventricle 50 by the mitral valve 45. Blood is delivered into the rightatrium 20 from the upper half of the body via the superior vena cava 15,and from the lower half of the body via the inferior vena cava 17. Thetricuspid valve 25 is opened by concurrent contraction of the rightatrium myocardium (i.e., muscle tissue) and the right ventricularpapillary muscles 27 thereby allowing blood flow from the right atrium20 into the right ventricle 30, and then closes when the papillarymuscles 27 relax. When the myocardium of the right ventricle 30contracts, blood is forced from the right ventricle 30 through thepulmonary valve 35 into the pulmonary artery 37 which delivers the bloodinto the lungs wherein it is oxygenated. The oxygenated blood is thenreturned into the left atrium via pulmonary veins 38 and 39. Theoxygenated blood flows from the left atrium into the left ventricle whenthe mitral valve 45 is opened by concurrent contraction of the leftatrium myocardium and the left ventricular papillary muscles 47 therebyallowing blood flow from the left atrium 40 into the left ventricle 50,and then closed when the papillary muscles 47 relax. The oxygenatedblood is then forced out of the left ventricle 50 through the aorticvalve 55 into the aorta which delivers the oxygenated blood tothroughout the body via the peripheral vascular system.

Every rhythmic ‘beat’ of the heart involves three major stages: atrialsystole, ventricular systole and complete cardiac diastole. Electricalsystole is the electrical activity that stimulates the muscle tissue,i.e., the myocardium of the chambers of the heart to make them contract.Referring to FIG. 3( b), atrial systole 110 is the period of contractionof the heart muscles (i.e., myocarida) encompassing the right and leftatria 20 and 40. Both atria 20 and 40 contract concurrently withpapillary muscle 27 and 47 contraction thereby forcing open thetricuspid valve 25 and the mitral valve 45 as shown in FIG. 1.Electrical systole, i.e. electrical depolarization of the atria 20 and40 begins within the sinoatrial (SA) node located in the right atriumjust below the opening to the superior vena cava. The conductionelectrical depolarization continues to travel in a wave downwards,leftwards and posteriorly through both atria depolarising each atrialmuscle cell in turn. It is this propagation of charge that can be seenas the P wave on an ECG as exemplified in FIG. 3( a). This is closelyfollowed by mechanical systole i.e., mechanical contraction of the atriawhich is detected on a BCG (FIG. 3( d)) as an impact (i.e., “h” peak)and. recoil (i.e., “i” valley) wave pattern. As the right and left atria20 and 40 begin to contract, there is an initial high velocity flow ofblood into the right and left ventricles 30 and 50 detectable as the “j”peak on the BCG (FIG. 3( d)). Continuing atrial contraction as thetricuspid valve 25 begins to close forces an additional lower velocityflow of blood into the right and left ventricles 30 and 50. Theadditional flow of blood is called the “atrial kick” and is shown inFIG. 3( d) as the “a-a¹” wave pattern. After the atria are emptied, thetricuspid and mitral valves 25 and 45 close thereby giving rise to thefootward “g” wave pattern on the BCG as shown in FIG. 3( d).

Referring to FIG. 3( b), ventricular systole 120 is the contraction ofthe muscles i.e., myocardia of the left and right ventricles 30 and 50,and is caused the the electrical depolarization of the ventricularmyocardia giving rise to the QRS complex in a ECG plot as shown in FIG.3( a). The downward Q wave is caused by the downward flow ofdepolarisation through the septum 33 along a specialized group of cellscalled “the bundle of His”. The R wave is caused by depolarization ofthe ventricular muscle tissue, while S wave is produced bydepolarization of the heart tissue between the atria 20 and 40 andventricles 30 and 50. As the depolarization travels down the septum andthroughout the ventricular myocardia, the atria 20 and 40 and sinoatrialnode start to polarise. The closing of the tricuspid and mitral valves25 and 45 mark the beginning of ventricular systole and cause the firstpart of the “lub-dub” sound made by the heart as it heats. Formally,this sound is known as the “First Heart Tone” and is produced during theperiod of time shown in FIG. 3( b) as S₁. As the electricaldepolarization of the ventricular myocardia peaks, as exemplified by the“R” peak shown in FIG. 3( a), the AV septum 33 separating the right andleft ventricles 30 and 50 contracts causing an impact, i.e., the “H”peak and a recoil i.e., the “I” valley detectable on a BCG as shown inFIG. 3( d). The ventricular contraction forces the blood from the rightventricle 30 into the pulmonary artery 37 through the pulmonary valve35, Lind from the left ventricle 50 into the aorta 60 through the aorticvalve 55 under very high velocity thereby causing the “J” wave in the

BCG as shown in FIG. 3( d). The deceleration of blood flow from the leftventricle 50 into the aorta 60 causes a footward decline in the BCGresulting in the “K” wave (FIG. 3( d). As the left ventricle 50 empties,its pressure falls below the pressure in the aorta 60, and the aorticvalve 55 closes. Similarly, as the pressure in the right ventricle 30falls below the pressure in the pulmonary artery 37, the pulmonary valve35 closes. The second part of the “lub-dub” sound, i.e., the “SecondHeart Tone” is produced during the period of time shown in FIG. 3( b) asS₂ and is caused by the closure of the pulmonary and aortic valves 35and 55 at the end of ventricular systole thereby giving rise to theheadward “L” wave detectable on a BCG as shown in FIG. 3( d)Concurrently with the closing of the pulmonary and aortic valves 35 and55, the AV septum 33 relaxes and moves headward, and the ventricularmyocardia is re-polarized giving rise to the “T” wave in thecorresponding ECG as shown in FIG. 3( a).

Cardiac diastole is the period of time when the heart 10 relaxes aftercontraction in preparation for refilling with circulating blood. Atrialdiastole is when the right and left atria 20 and 40 are relaxing, whileventricular diastole is when the right and left ventricles 30 and 50 arerelaxing. Together, they are known as complete cardiac diastole 150 asshown in FIG. 3( b). During the period of atrial diastole, the rightatrium 20 is re-filled by deoxygenated blood returning from the upperhalf of the body via the superior vena cava 15 and from the lower halfof the body via the inferior vena cava 17, while the left atrium isre-filled with oxygenated blood returning from the lungs via pulmonaryveins 35 and 39. Re-filling of the atria 20 and 40 causes a downward “M”wave the BCG FIG. 3( d) early in diastole which coincides withrepolarization of the bundle of His cells, which is shown as the “U”wave in FIG. 3( a). As the right and left atria 20 and 40 arc filled totheir maximum capacities, the reflux of blood against the tricuspidvalve 25 and mitral valve 45 cause an upward “N” wave in the BCG asshown in FIG. 3( d).

In summary, an ECG, as exemplified in FIG. 3( a) provides information onthe rhythmic formation, propagation and regeneration of electricalsignals within the heart muscles wherein: (a) the P wave results fromelectrical depolarization of the right and left atria signalling theonset of atrial systole during which time the right and left atriacontract, (b) the QRS wave pattern results from depolarization of theright and left ventricles signalling the onset of ventricular systoleduring which time the right and left ventricles contract, (c) thesubsequent T wave is produced by electrical repolarization of theventricular myocardia, and (d) the U wave is produced by electricalrepolarization of the bundle of His cells. The T and LT waves arenotoriously hard to locate and annotate due to their slow slopes and lowamplitudes.

The BCG, as exemplified in FIG. 3( d), records the vigor of cardiacejection of blood from the atria and ventricles, and the speed offilling of the atrial chambers during the diastolic period. Morespecifically, the BCG provides information on the mechanical functioningand related physical movements of the heart muscles, valves, and relatedflows of blood into, between and out of the atria and ventricles as aconsequence of electrical depolarization and re-polarization of theheart tissues. As the heart pumps blood from the right and left atriavia the right and left ventricles into the pulmonary artery and theaorta, and as the blood flow returns to the left and right atria, recoilpressures in the opposite directions are applied by the body. Thepumping pressures result in headword BCG wave peaks, while the recoilpressures on bloodflow result in the downward BCG wave peaks. The “h-i”wave component of the BCG shows the physical impact and recoil fromdepolarization of the SA node and related atrial movements. The “j-a-a¹”wave pattern records the impact and recoil of the heart in response toblood flow from the atria 20 and 40 into the right and left ventricles30 and 50. The “g” wave pattern is a caused by the closing of thetricuspid and mitral valves 35 and 45. The “H-I” wave pattern is causedby the impact and recoil of the septum 33 and corresponds to theisometric phase of ventricular systole during which time the heart isphysically twisting and moving upward within the chest cavity. The “J-K”wave pattern is caused by the initial highly forceful impact of bloodfrom the right and left ventricles into the pulmonary and aorticarteries (the J peak) followed by deceleration of blood flow in theaorta (the J-K slope). The L wave is caused by the movement of theseptum during isometric relaxation, while the M wave is caused by theflow of blood into the right atrium from the vena cava vessels and intothe left atrium by the pulmonary veins. The heart is physicallyrecoiling and moving downward in the chest cavity during isometricrelaxation. The N wave is caused by impact of blood onto the ventricularmyocardia at the end of early diastolic filling due to reflux.

Considerable energy is generated by the ventricular myocardia duringventricular systole, and the strength of ventricular contraction isfueled by the oxygen in the blood returning from the lungs into the leftventricle via the left atrium. About 80% of the oxygen in the bloodflowing through the left ventricle is removed to supply the ventricularmyocardial oxygen demand during ventricular systole. The cardiovascularsystems of most individuals under “resting” conditions, can supplyadequate amounts of oxygen during coronary perfusion to provide regularrepeating ECG and BCG patterns as exemplified in FIGS. 3( a) and 3(d).When healthy individuals are placed under stressed conditions, e.g.,exercise, it is known that as the heart rate increases to providesufficient oxygen to the maintain efficient cardiovascular functionwhile supplying additional oxygen to meet the demands from theperipheral musculature, the related ECG and BCG wave patterns reproducethe typical repeating wave patterns as illustrated in FIGS. 3( a) and3(d) but the slopes and amplitudes of the wave patterns increasesignificantly. However, individuals experiencing some debilitation intheir cardiovascular physiology and function, when stressed, tend toproduce BCG signals that show significant variations in their repeatingBCC wave patterns when compared to their BCG produced under “resting”conditions. FIGS. 4( a)-4(d) show four types of exemplary BCG signalsthat are divided into separate classes of cardiovascular abnormalitiesbased on the Starr classification system (Starr, 1964, Journal of theAmerican Medical Association 187: 511). In Class 1 (FIG. 4( a)), all BCGwave patterns are normal in contour. In Class 2 (FIG. 4( b)), themajority of the BCG wave patterns are normal but one or two of thesmaller wave patterns in each respiratory cycle are abnormal in Class 3(FIG. 4( c)), the majority of the BCG wave patterns are abnormal incontour and usually, only a few of the largest wave patterns of eachrespiratory cycle remain normal. Lastly, in Class 4 (FIG. 4( d)), thereis such complete distortion in the BCG wave patterns that none of thewaves can be identified with confidence, and it is difficult todetermine the onset of each rhythmic cycle. In general, a normal healthyperson should belong to the Starr Class 1 (FIG. 4( a)), while a personproducing BCG wave patterns that fall into the Starr Classed 3 or 4(FIG. 4 (c)) or 4(d)) has significant cardiovascular abnormalitiesand/or malfunctions.

We have surprisingly discovered that, regardless of the type of BCG wavepattern produced by an individual under stressed conditions in referenceto the Starr classification system, it is possible to synchronize theindividual's rhythmic BCG pattern with their ECG signal undernon-stressed, i.e., resting stage conditions, and then characterize theindividual's cardiac function by calculating a plurality of thefollowing parameters:

(1) stroke volume: the amount of blood ejected from the left ventricleduring systole. Stroke volume (SV)=end diastolic volume (EDV)−endsystolic volume (ESV);

(2) cardiac output: the volume of blood pumped by the left ventricle perminute, calculated by multiplying the stroke volume by the number ofheart beats per minute. Cardiac output (CO)=SV×heart rate (HR measuredin beats per minute);

(3) ending diastolic volume: the volume of blood contained in the leftventricle at the end of the rest phase when the left ventricle is at itsfullest;

(4) ending systolic volume: the volume of blood left in the leftventricle at the end of the systolic period when the ventricle containsits lowest volume;

(5) ventricular ejection fraction: the percentage of the endingdiastolic volume that is ejected during each heart beat. Ejectionfraction (EF)=SV/EDV;

(6) cardiac output index: the volume of blood pumped by the leftventricle per minute normalized to the body surface area (measured inmeters²). Cardiac output index (CI) CO body surface area(BSA)=SV×HR/BSA;

(7) Pre-ejection period: The time from the Q-wave peak on the ECG to theopening of the aortic valve;

(8) Cardiac performance index (CPI) (isovolumetric relaxationtime+isovolumetric contraction time)/Ejection time (ET). The CPI canalso be calculated as the (time period between the I-peak and theL-peak) ET. The CPI can also be calculated as the (time period betweenaortic valve opened and aortic valve closed)/(time period between theI-peak and the L-peak).

The quantifications of the above parameters are dependent onsynchronizing, as illustrated in FIGS. 3( a) and 3(d), the R wave peakon an ECG caused by the depolarization of the ventricular muscle tissuewith the H peak on a corresponding BCG which signals the rapid increasein intraventricular pressure caused by the impact of the septum as thedirect consequence of the depolarization of the ventricular musclepressure. Since the H-wave and I-wave on a BCG are caused by the impactand recoil of the septum concurrent with depolarization of theventricular muscle tissue, (a) the time duration of the H-I wave, i.e.,the isovolumetric contraction time, and (b) the distance between the Hand I peaks over the duration of that wave, can be measured. These dataenable calculation of the slope of the H-I wave and the time to maximumvelocity of the blood flow resulting from the ventricular contractionwhich results in rapid blood flow into the aorta thereby causing theJ-peak. The subsiding blood flow into the aorta from ventricle resultsin the K-Peak. Since most individuals at resting stage, reproduce all ofthe H-I-J-K-L-M-N peaks of a “normal” looking BCG pattern, thesynchronized H-peak, and the detected I-peak and J-peaks can be used tosequentially find and mark the remaining K-L-M-N peaks. Marking each ofthese peaks enables precise calculation of the H-I slope, the I-J slope,the J-K slope, the K-L slope, the L-M slope, and the M-N slope. Thesedata enable calculations of the time to maximum velocity for each slopethereby enabling calculation of the volumes of blood flow, and thepositive and negative pressure values that are exerted on and by thevarious heart muscles and valves. Furthermore, it is also possible toback-calculate from the synchronized H-peak and precisely mark thepreceding g-a¹-a-j-i-h wave patterns.

When individuals with healthy cardiovascular systems, i.e., those withinthe Starr Class 1 range, are stressed such that their heart ratesincrease significantly to supply adequate oxygen in the blood streamthroughout the body, the slopes of their H-I and J-K wave patterns willincrease in height, have steeper slopes and have shorter time period,while the L-M-N waves will repeat distinctly, regularly and their slopesoften become steeper. However, individuals with cardiovascularabnormalities and malfunctions, when stressed, will produce H-I and J-Kslopes that are decreased in height and become longer, i.e., flatter,while L-M-N peaks tend to flatten out as shown in FIGS. 4( b) and 4(c).In cases where the severity of the cardiovascular abnormalities andmalfunctions are increased, the heights of the H, J, L, and N peaks aresignificantly reduced to the point where the H-I, K-L, L-M and M-Nslopes are similarly elongated and irregular as shown in FIG. 4( c).Table 1 shows a summary of various types of cardiovascular abnormalitiesand their effects on ECG and BCG wave patterns.

TABLE 1 Cardiovascular abnormality ECG Wave Patterns BCG Wave PatternsIschemic Heart hyperacute T wave (tall T wave) increased amplitude in K,J, L, M Diseases (IHD) ST segment Changes. peaks T wave inversion. broadK wave Q wave longer than 0.04 sec. fused H-J wave patterns S in V1 andV2 + R in V5 expiration. R in I + S inIII >25 mm notched J waves changesin Q-I, Q-J, I-J slopes Sinus Arrhythmia: typical ECG wave patternsprolonged H-I-J wave pattern tachycardia relating to heart rate, P waveor often appears as Starr Class 3 or 4 bradycardia QRS wave patternswave patterns Nonsinus Arrhythmia: ECG shows variable different P-primarily produce Starr Class 3 or ventricular & atrial QRS wavepatterns 4 wave patterns flutter/fibrillation Hypertension variable ECGwave patterns. tall L wave. T inversions large H wave. large S or Rpeaks. H wave fused into the J wave some ECG fluctuations similar tothose for IHD

We have discovered that the H-I-J-K-L-M-N wave peak data collected andcalculated from the synchronized BCG and ECD signals under restingconditions, can he used as reference points to detect and identifydifferent types of potential cardiovascular abnormalities by the changesthat occur in one or more of the H-I, K-L, L-M, and M-N slopes when theindividual is placed under stressed conditions. It is important notethat regardless of whether an individual is under resting or stressedconditions, synchronization of the H-peak on the BCG with the R-peak onthe ECG during resting conditions will enable during stressedconditions, the precise marking of where the H-peak should occur on theBCG from the R-peak on the ECG. It is then possible to mathematicallydetermine where the subsequent I-J-K-L-M-N peaks should have occurred.By referencing the synchronized h-i-j-a-a¹-g-H-I-J-K-L-M-N and wavepeaks and H-I, I-J, J-K, K-L, L-M, M-N slopes produced by the individualunder resting conditions, it is possible to identify and characterizethe changes in the physical movements of the heart muscles and valves,and in the rates and patterns of blood flow into, through and out of theheart under stressed conditions. For example, significant decreases inthe H and J peaks accompanied by elongation of the H-I and J-K slopesunder stress conditions indicate that there is (a) a reduction in therate of increase in intraventricular pressure in response todepolarization of the ventricular muscle pressure, i.e., there is lessventricular contractive force being generated during ventricularsystole, which results in (h) less ejective force exerted on blood flowduring ventricular contraction thereby resulting in a smaller J peak.The reduction in the H and J peaks is primarily as a consequence ofinsufficient oxygen delivery to the heart muscles in the blood returningfrom the lungs to the left atrium to supply the energy required forcontraction of the left ventricle. Prolonged insufficient supply ofoxygenated blood to the left ventricle will result in the decreases inthe H and J peaks becoming more pronounced while the H-I and J-K slopesbecome more elongated. Individuals with severely reduced cardiovascularfunction will have significantly increased heart rates under stress,which can be detected by a significantly reduced time span between theS₁ and S₂ periods, i.e. the time period between the I peak signalingseptum recoil during ventricular contraction and the L peak signallyventricular relaxation during which time the aortic valve is closed bybackflow of blood ejected from the left ventricle. Malfunctioning in theaortic valve, e.g., incomplete closure or leakiness by the aortic valveresults in a greater impact on the left ventricular wall during theearly period of diastole and causes a larger spike, i.e. height in the Npeak. Reduction in the height of the j peak and an elongation of the j-aslope under stressed conditions indicates that the right and left atriaare contracting with less force compared to the resting stage, whiledisappearance of the a¹ peak indicates that the right atrium is notdelivering the same pressurized volume of blood into the right ventriclefor subsequent delivery into the pulmonary artery for transport to thelungs. A reduction or disappearance in the g wave indicates malfunctionor abnormalities in closure of the tricuspid and/or mitral valvesresulting in backflow leakage from the right and left ventricles intothe right and left atria. When an individual with a malfunctioningand/or abnormal cardiosystem is relieved from the stressed conditionsand returns to a resting stage, their ECG and BCG patterns to the normalpatterns previously recorded before the onset of the stress.

An exemplary embodiment of the present invention for monitoring thephysiological condition of the cardiovascular system and detectingabnormalities is shown in FIG. 5 and generally comprises at least: (1)one device configured for detecting electrical depolarization andre-polarization of an individual's heart tissues and for transmittingsuch information as a ECG signal, (2) one device configured fordetecting physical movements on and/or within the individual's heart andrelated movements on their body surfaces and for transmitting suchinformation as a BCG signal, (3) a device configured for receiving theECG and BCG signals and conditioning at least one of the signals, (4) ananalog-digital converter for converting the signals into digital datathat can be processed and stored, (5) a microprocessor for computing,analyzing, reporting, transmitting and storing the digital data, (6) acomputer software program comprising at least one algorithm configuredfor analyzing the ECG and BCG signals to: (a) detect the P-QRS peaks inan ECG signal, (h) detect and mark the H-I-J peaks in a BCG, (c)synchronize the H peak of the BCG signal with the R peak of the ECGsignal, and (d) provide synchronized ECG and BCG signal outputs, and (7)a graphical user interface (GUI) program written in C++ language.

The system of the present invention may be suitably provided with apulseoximeter configured to concurrently detect at least the amount ofoxygen in the individual's blood and changes in the blood volume intheir skin and transmit these data one of the device configured forreceiving the ECG and BCG data or alternatively, to the microprocessor.The pulseoximeter may be optionally configured to detect and transmitthe individual's heart rate. The system of the present invention maybeoptionally provided with a device configured to detect sounds made bythe heart during its rhythmic systole-diastole periods and to transmit aphonocardiogram signal to the signal conditioning device. The system ofthe present invention may he optionally provided with a deviceconfigured to provide images of the heart during its rhythmicsystole-diastole periods and to transmit an echocardiogram signal to thesignal conditioning) device. The computer program may optionallycomprise a plurality of cooperating algorithms.

The device configured for receiving the ECG and BCG signals and theanalog-digital converter may comprise a suitably configured motherboardprovided with suitable electronic devices known to those skilled inthese arts. The motherboard may be additionally provided with amicroprocessor configured for receiving and running the software programcomprising one or more mathematical algorithms and/or heuristicalgorithms to at least separately process, analyze and synchronize the Rpeaks and H peaks of the concurrently received ECG and BCG signals andto provide an output comprising at least synchronized ECG-BCGwave-pattern signals. The computer software program may be suitablyprovided with an additional or optionally, a plurality of algorithmsconfigured to heuristically separately process, analyze and synchronizethe concurrently received ECG and BCG signals, and then to heuristicallyidentify and mark the h-i-j-a-a¹-g and I-J-K-L-M-N peaks on thesynchronized BCG signal. The computer software program may be suitablyprovided with at least one addition algorithm or optionally, a pluralityof algorithms configured to process, compare, and analyze pluralities ofsynchronized ECG and BCG signals and to provide outputs relating to thesimilarities and differences among and between the pluralities ofsynchronized ECG and BCG signals.

FIG. 6 shows an exemplary 4-step flowchart according to one embodimentof the present invention, for processing and synchronizing concurrentlyproduced ECG and BCG signals. The first step comprises conditioning ofconcurrently produced ECG and BCG signals to remove extraneous noisecomponents thereby providing signal outputs that are transmitted withminimum relative loss or maximum relative gain. A suitable method forconditioning ECG and BCG signals is to pass each signal separatelythrough fifth-order Butterworth filters wherein: (a) for the ECG signal,the high-pass cutoff frequency is set at about 40 Hz and the low-passfilter is set at about 1 Hz, and (b) for the BCG signal, high-passcutoff frequency is set at about 25 Hz and the low-pass filter is set atabout 1 Hz, The second step is to detect the R wave in the filtered ECGsignal with an algorithm. A suitable algorithm may be developed byexploiting the curve-length concept

which, in reference to FIG. 7, illustrates how the lengths L1 and L2 areable to characterize the shape of the curves, given a certain timeinterval DT. This principle can be applied to detect the wave frontsthat characterize the beginning and the end of an episode arc- lengthrelative to the i-th sample with the chord length, obtaining:

  (1)

L is the total estimated length of the episode, Tx is the samplinginterval, yi-yi-1 represents the i-th increment and n is a roughestimate of the duration of the episode (or waveform) to be detected: inthis case n is an estimate of QRS duration. L can also be written:

$\begin{matrix}{L = {{{Tx} \cdot {\sum\limits_{i = 0}^{n - 1}\; \sqrt{1 + \frac{( {y_{i} - y_{i - 1}} )^{2}}{{Tx}^{2}}}}} = {{Tx} \cdot {\sum\limits_{i = 0}^{n - 1}\; \sqrt{1 + \frac{{Dy}^{2}}{{Tx}^{2}}}}}}} & (2)\end{matrix}$

Finally, centering the computational window on the i-th sample andcalling w=n/2,a recursive low computational cost form is obtained thatmay be incorporated in to computer software programs using assemblylanguages for DSPs processors known to those skilled in these arts:

  (3)

The third step is to identify the H peak from the conditioned BCGsignal, then synchronize the H peak with the R peak from the ECG signal,after with the conditioned BCG signal is parsed to locate and mark theh-i-j-a-a¹-g and I-J-K-L-M-N peaks, and then, average the conditionedBCG

Suitable heuristic algorithms for (a) synchronizing the H peak with theR then (b) parsing the conditioned BCG signal is parsed to locate andmark the h-i-j-a-a¹-g and I-J-K-L-M-N peaks, and then, (c) averaging theconditioned BCG signal, may be developed by using the ECG's R peaks asthe synchronization points for the cycle-by-cycle length determination.Each cycle length is than divided into intervals according to the samplerate of the signals. The number of the intervals can be programmed andexperimentally determined. An example is 2500 samples equivalent to 1.2seconds of the acquired signal. The assigned intervals allow the signalprocessing. The segment points are than associated with the ECG pickvalues, when possible and as the additional synchronization option. Thesegmented signal is used for maxima and minima determination followed bythe BCG's letter assignments. Each segment can be searched for a localminimum or maximum. The number of segments and their programmedassignments permit on a practical adjustments and experimental set-upsaccordingly to the subject group and analysis requirements.

The assignments generally follow the steps listed below for thesegmented ECG and BCG signals:

-   1.first segment in BCG signal after R pick or the segment with the R    pick is searched for a local maximum which determines H value of the    BCG-   2. next local minimum of BCG signal segments (following H) is found    for the assignment of I value of BCG-   3. from I value the next segments are searched for the local maximum    and J assignment, the next local minimum can be K pick of BCG    signal,-   4. synchronize and associate the segments and values to the ECG    signal,-   5. next local maximum of the ECG signal which follows J maximum (BCH    signal) is T pick, the identification of the T permits on the    re-synchronization of the segments,-   6. the search of the segments following T pick determines the L    (local maximum) and M (the local minimum),-   7. the next assignment after L and M is the result of the search of    the next local maximum which becomes N pick of the BCG signal,-   8. the segmentation permits on the time interval determination and    the back calculation of the time related to the specific events    (pick values),-   9. the assignments are repeated for each next cycle of BEG signal as    determined by R pick synchronization reference,    after which, the cycle-by-cycle assignments can he averaged or    considered separately.

The fourth step is to producing synchronized and marked outputs of theECG and BCG signals, and transmitting the outputs to at least oneelectronic processing device, one data storage device and one visualoutput device. Exemplary suitable visual output devices include displaymonitors, printers and plotters. The data produced by the individual asdescribed will serve as the resting-stage reference points forsubsequent physiological stress testing outputs, as will be described inmore detail below.

Another embodiment of the present invention comprises detecting,transmitting, conditioning, synchronization, and processing of aplurality of signals produced by an individual's cardiovascular systemduring resting stage conditions, and storing the digital data developedtherefrom in a data storage device. Suitable signals are ECG signals andBCG signals. The signals may optionally or additionally, comprisephonocardiogram and/or echocardiogram signals. While remaining connectedto the system of the present invention, the individual is then placedunder stressed conditions for real-time ongoing detection, transmission,conditioning, synchronization and processing of the signals output bythe individual's cardiovascular system to produce a synchronized ECG-BCGsignal set showing the effects of stress on the signal outputs. Thestressed signal outputs can then be compared using at least onealgorithm, to the resting-stage signal outputs for detection,quantification and assessments of stress-effected variations in thesignal wave patterns and h-i-j-a-a¹-g-H-I-J-K-L-M-N peaks.

After acquisition, processing and extraction of BCG-ECG signal pickvalues and time intervals the comparison of the time-pick values isconducted. The comparison includes the following:

-   1. pick values and their respective normalized amplitude values; the    lower or higher values are determined in comparison of the pre and    post exercise assessment,-   2. the time intervals related to the pick vales are compared and the    differences are derived,    the differences are determined on cycle-by-cycle basis; the extreme    values and the averaged values are recorded and reported.

The computer software program of the present invention may beadditionally configured to average synchronized outputs for anindividual's resting and stressed stages, and then to overlay theaveraged synchronized outputs to enable visual observation and analysesof the cardiovascular signal outputs. Since the data for each signalrecording session is storable in a data storage device, it is possibleto collect resting stage signal data from an individual over an extendedperiod of time, e.g., months or years or decades, and then preciselydetect and assess physiological changes that may have occurred in theindividual's resting stage cardiovascular system during these timeperiods.

The graphical user interface (GUI) of the present invention isconfigured to manage the acquisition, analysis, storage and reporting oflarge sets of ECG-BCG waveforms. A backend data management module may beoptionally provided for efficient interfacing between the GUI and thesynchronized ECG-BCG data stored in a suitable database. An additionalmodule may be provided for computer-aided selection of the individualtailored data-analysis algorithms for analysis and synchronizing ofcertain types of BCG signals, and optionally, computer-selectedcombinations of data-analysis algorithms. It is within the scope of thisinvention that the GUI is suitably configured as shown in FIG. 8:

-   (a) to provide at least on module configured receive a plurality of    signals from an individual's cardiovascular system, and then (i)    process, (ii) analyze, (iii) optimize, (iv) transform, (v)    synchronize, and (vi) generate at least one output comprising at    least one synchronized signal wave pattern,-   (b) with a computer software program configured to provide a    computer-aided process for selection of a suitable data-analysis    algorithm for processing an incoming stream of plurality of signals    from an individual's cardiovascular system, and optionally, for a    selection of a combination of suitable data-analysis algorithms, and-   (c) to provide a data flow management module for communicating and    cooperating with a data storage device, and-   (d) to provide an outputs management module for communicating    synchronized ECG-BCG signal outputs to devices exemplified by    monitors, screens, printers and plotters.

Referring to FIG. 8, the GUI is in windows GUI format through MicrosoftFoundation Class (MFC). It provides the basic system layout, waveformdisplay, as well as various buttons, inputs, and fields associated withdata management and analysis function calls FIG. 9. The GUI provides theuser access to retrieve and analyze the waveforms from the database. Amodel GUI drawing is attached in the appendix to provide more detail tothe basic design of the GUI. The database management module is a libraryof general functions providing the User Interface Module access to thedatabase. Basic functions may include, “read”, “write to datatable”,“add subfolder”, “retrieve wavefile”, and “save/resave wavefile”. Thewaveform display module suitably comprises a library of generalfunctions. It may additionally contain basic waveform display functionssuch as “draw and erase waveforms”, “scrolling display and zooming”,“select points on waveform”, “select cycles on waveform”, and “getvalues on wavepoints”. The waveform analysis module suitable comprises alibrary collection of functions. These functions are linkable functionsthat the User Interface Module can call upon to provide outputs to thewaveform analysis module. The basic function groups will includealgorithms to “detect wave slopes”, “amplitude”. “interwavelet delays”,“cycle detection”. “averaging”, and other analysis algorithms known tothose skilled in these arts to be useful for analyzing ECG or BCGsignals.

FIG. 10 shows an exemplary basic layout for a database structure usefulto storing sets of ECG-BCG waveforms provided by the present invention.The database is contained inside a main folder, the database folder.This database folder contains a SQL (similar to Access) type data table.The SQL data table stores information for each subject and references tothe waveforms associated (FIG. 1). The waveform data files for eachsubject are stored under subfolders located wider the same main folder.There may be several waveform data files during a single session for thesame subject, thus an exemplary naming convention has been establishedto maintain reliable referencing. The exemplary file naming conventionis as follows: first, 4-digit subject ID is placed, followed by anunderscore, then the location of the BCG reading is indicated byappending either PMI (4/5-intercostal) or STR (sternal), followed byanother underscore, then pre- or post-exercise reading is indicated byappending PRE (for pre-exercise) or POS (for post-exercise), followed bythe number of the recording, followed by another underscore, thenfinally the date is appended using the year-month-date convention(YYYYMMDD). The template for the filename would read the as follows:

XXXX_PMI/STR_(—PRE/POS#)_YYYYMMDD

An exemplary method for the use of the system of the present inventionfor monitoring the physiological condition of an individual'scardiovascular systems and for early identification cardiovascularabnormalities and malfunctions is provided below.

Referring again to FIG. 5, the first step is to collect and input intothe GUI, the individual's: (a) medical history relating to theircardiovascular system, (b) lifestyle characteristics such smoking,drinking, nutrition, drug use habits and other lifestyle habits, (c)physical activity level; and (d) physical and genetic informationincluding race, weight, height, circumference of their body around thehips, circumference of their body around the waist, age, and sex. Thesecond step is to measure their blood pressure with a suitable bloodpressure measuring device exemplified by CAS Vital Signs Monitors Models740, 750C and 750 E (CAS Medical Systems Inc., Branford, Conn., USA). Itis suitable for the individual to remain interconnected with the bloodpressure measuring device for the duration of the testing period. Thethird step is to attach an appropriate number of electrocardiograph(ECG) electrodes to appropriate sites on the individual's body and thenconnect the ECG electrodes to a suitable ECG system. The fourth step isfor the individual to lie in a prone position after which, a suitableballistocardiograph (BCG) accelerometer as exemplified by those suppliedby Brüel&KjEer (Skodsborgvej 307, DK-2850, latterum, Denmark) isattached to the base of the individual's sternum with hypoallergenic.double-sided adhesive tape. It is also suitable to clip a pulseoximeterto the individual's finger. Exemplary suitable pulseoximeters includeNonin 8600 pulseoximeters (Nonin Medical Inc., Plymouth, MM, USA) andCAS Vital Signs Monitors Models 740, 750C and 750 E (CAS Medical SystemsInc.) The sixth step is to record the individual's resting-stage ECG,BCG, blood pressure, heart rate and blood oxygen concentration signaldata for a selected period of time while they are lying in a proneposition and breathing normally. An exemplary suitable resting, stagedata collection period is about three minutes, but this data collectionperiod may be adjusted as determined to be appropriate by the medicalpersonnel conducting the testing of the individual. It is preferablethat a plurality of BCG data collections is conducted during theresting-stage data collection period. A suitable number of BCG datacollections during this period is three. The seventh step is for theindividual to perform a selected physical exercise for a selectedsuitable period of time appropriate for the selected physical exercise.Exemplary suitable physical exercises include pedaling on a stationarybicycle, running or walking on a treadmill, manipulating a StairMaster®exercise device (StairMaster is a registered trademark of StairMasterSports/Medical Products, Inc., Vancouver Wash., USA), jogging, swimmingand the like. The eighth step is for the individual to lie down into aprone position immediately after the period of physical exercise hasended for recording of the individual's post-exercise ECG, BCG, bloodpressure, heart rate and blood oxygen concentration signal data for aselected period of time. An exemplary suitable post-exercise datacollection period is about three minutes, but this data collectionperiod may be adjusted as determined to be appropriate by the medicalpersonnel conducting the testing of the individual. It is preferablethat a plurality of BCG data collections is conducted during theresting-stage data collection period. A suitable number of BCG datacollections during this period is three.

The subject information. resting-stage, and post-exercise data inputsare transmitted to the database engine where they arc stored in separatefiles in the database, and are accessible for processing,synchronization, and analyses by the algorithms of the present inventiondisclosed herein for synchronization of the R peak of the ECG signal andthe H peak of the BCG signal for each set of ECG and BCG signalsconcurrently collected from the individual during their rest-stage andpost-exercise periods. The processed data is stored in separate files inthe database, and are displayable on suitable monitors and screens, andprintable by suitable printers and plotters. Comparisons of theindividual's resting-stage and post-exercise synchronized ECG-BCG wavepatterns generated by the algorithms of the present inventions willenable detection and assessments in stress-induced changes in theindividual's BCG wave patterns and related h-i-j-a-a¹-g-H-I-J-K-L-M-Npeaks.

In accordance with one exemplary embodiment, the system may be used as aroutine testing method in a clinical environment as exemplified by aMedical Doctor's office, a walk-in clinic, a clinical laboratory, atesting facility associated with a medical research institute, a testingfacility associated with a hospital, and the like.

In accordance with another exemplary embodiment, the system may beoptionally adapted for employment in exercise and training facilitiesfor observing, recording and storing changes in an individual'scardiovascular system during periods of exercise and training for thepurposes of monitoring improvements in cardiovascular fitness and fordetection of onset of potential cardiovascular malfunctions.

in accordance with another exemplary embodiment, resting-stagecardiovascular data and related synchronized ECG-BCG wave patterns maybe collected from a plurality of individuals, compiled and stored in adatabase file for use as a “population” sized reference point forcomparing individuals' resting-stage synchronized ECG-BCG wave patterns.It is within the scope of the present invention to separate and grouppluralities of resting-stage synchronized ECG-BCG wave patterns inaccordance to, for example, the

Starr classification system to provide “population” sized referencegroups of healthy individuals with ideal synchronized ECG-BCG wavepatterns (i.e., resting-stage Class 1), individuals with somewhat lessthan ideal synchronized ECG-BCG wave patterns (i.e., resting-stage Class2), individuals whose synchronized ECG-BCG wave patterns showdebilitation of cardiovascular function under resting conditions (i.e.,resting-stage Class 3), and individuals whose synchronized ECG-BCC; wavepatterns show significant debilitation of cardiovascular function underresting conditions (i.e., resting-stage Class 4).

The system and methods of the present invention for monitoringcardiovascular physiological conditions and for detecting relatedabnormalities and malfunctions are described in more detail in thefollowing examples.

EXAMPLE 1

An exemplary system of the present invention was configured as shown inFIG. comprising the following components:

-   1. CSA 750C Multi-Parameter Monitor (CAS Medical Systems Inc.) for    monitoring blood pressure, heart rate and blood oxygen levels.-   2. Burdick® EK10 12 lead, single channel electrocardiograph (Cardiac    Science Corp., Bothell, Wash., USA) for detection and transmission    of ECG signals.-   3. Brüel & Kjxr® (Brtiel & Kjxr is a registered trademark of Brtiel    & Kjeer Sound & Vibration; Measurement AIS, Nrurn, Denmark) Type    4381 accelerometer coupled with a Brüel & Kjxr® Type 2635 charge    amplifier for detection and transmission of BCG signals.-   4. LahVIEW® (Lab VIEW is a registered trademark of National    Instruments Corp., Austin, Tex., USA) 8.2 data acquisition system    installed on an IBM laptop computer, for concurrently receiving ECG    and BCG signals from the ECG and BCG instruments-   5. A software program comprising the algorithms described herein for    conditioning and synchronizing ECG and BCG, and configured to    communicate with the LabVIEW® 8.2 data acquisition system.-   6. A database program configured to receive, store and display    conditioned raw and synchronized ECG and BCG signal sets.-   7. A stationary exercise cycle.

The system was used to collect, condition, synchronize, process,analyze, store and report resting-stage and post-exercise cardiovasculardata from 142 individuals, Each individual was assessed for a period of30 minutes as follows: First, their medical history was filled in on aquestionnaire comprising the following questions:

-   -   (1) medical history of their heart (including all know heart        conditions),    -   (2) lifestyle habits (i.e. smoking drinking, drug use, stress        levels, etc.),    -   (3) physical activity level,    -   (4) race,    -   (5) weight,    -   (6) height,    -   (7) hip circumference,    -   (8) waist circumference,    -   (9) body fat %,    -   (10) age, and    -   (11) sex.

Next, the individual's blood pressure was recorded after which, ECGelectrodes to both of their shoulders and just above both hips, afterwhich the electrodes were attached to the Burdick® EK10electrocardiograph. Then, the Brüel & Kjxr® Type 4381 accelerometer andType 2635 charge amplifier were attached with hypoallergenicdouble-sided adhesive tape to the base of the individual's sternum.Then, the pulseoximeter provided with the CSA 750C Multi-ParameterMonitor was clipped onto one of the individual's forefingers andconnected to the Monitor. The individual then lay very still in a proneposition on a padded board while breathing normally while three1-minute-long BCG recordings were collected, with 1-minute rest periodsbetween each 1-minute recording period. The pulseoximeter,ballistocardiography, ECG, and blood pressure equipment weredisconnected from the individual who was was then asked to pedal thestationary exercise cycle for a 1-minute period or alternatively,depending on the physical condition of the individual, walk around a setcourse for 1 minute. They were then asked to again to lie down verystill in a prone position on the padded hoard while the equipment wasreconnected to the individual for collection of post-exercise bloodpressure, heart rate, blood oxygen concentration, ECG signals plus three1-minute BCG recordings, with 1-minute rests periods between each1-minute recording period.

The resting-stage and post-exercise ECG and BCG signals were conditionedby (a) passing the ECG signals through a fifth-order Butterworth filterwith the high-pass cutoff frequency set at about 40 HZ and the low-passfilter set at about 1 Hz, and (b) passing the BCG signals through afifth-order Butterworth filter with the high-pass cutoff frequency setat about 25 Hz and the low-pass frequency set at about 1 Hz. Thealgorithms described herein were applied to each ECG-BCG signal sets to(a) identify the R peaks, (b) synchronize the H peaks with the R peaks,(b) parsing the conditioned BCG signals to locate and mark theh-i-j-a-a¹-g and I-J-K-L-M-N peaks, and then, (c) averaging theconditioned resting-stage and post-exercise BCG signals.

EXAMPLE 2

FIG. 12 a shows the raw, unconditioned ECG and BCG signals produced by ahealthy individual with a normally function cardiovascular system,during a pre-exercise non-stressed resting-stage period. Additionalcardiophysiological data collected as described in Example 1, werestored in the system's database. FIG. 12 b shows the raw, unconditionedECG and BCG signals produced by the same individual after a period ofphysical exercise administered as outlined in Example 1. The R-peaks ofthe ECG signal during the pre-exercise resting stage (FIG. 12 a) wereused by the heuristic algorithms to mark and synchronize the BCG H-peakswith said concurrently collected ECG R-peaks. The heuristic algorithmssubsequently marked and correlated the subsequent I-J-K-L-M-N peaks andproduced the synchronized ECG-BCG cycle patterns shown in FIG. 13 a. Ina similar way, the R-peaks of the ECG signal during the post-exercisestage (FIG. 12 b) were used by the heuristic algorithms to mark andsynchronize algorithms subsequently marked and correlated the subsequentI-J-K-L-M-N peaks and produced the synchronized ECG-BCG cycle patternsshown. in FIG. 13 b. Finally, the software program compared and assessedsynchronized BCG patterns to determined if significant changes occurredin the physical functioning of the various heart components asexemplified by the vigor of cardiac ejection of blood from the atria andventricles, and the speed of filling of the atrial chambers during thediastolic period, and the related physical movements of the heartmuscles, valves, and related flows of blood into, between and out of theatria and ventricles. FIG. 13 c shows a comparison of the pre-exerciseand post-exercise synchronized BCG signals produced by the exemplarysystem of the present during one cycle, i.e. heart beat. In this healthyindividual, the pre- and post-exercise BCG patterns are identicalshowing that the electrical, physical and physiological components ofthe heart were not affected by the application of stress.

EXAMPLE 3

FIGS. 14 a and 14 b show the raw, unconditioned ECG and BCG signalsproduced by an individual before and after stress induced by physicalexercise as described in Example 1. This individual had previouslyexperience and recovered from a mild heart attack, and is in the processof modifying their lifestyle in order to strengthen their cardiovascularsystem. This individual's post-exercise heart rate was about 65%-70% (5beats in a 3-second interval) greater than the pre-exercise rate (3beats in a 3-second interval) (FIGS. 14 a and 14 b). More significant,however, are the changes that are evident after the signal conditioningto remove the background noise and synchronization of the BCG signalswith the ECG signals (FIGS. 15 a and 15 b), that show the increasedheart rates is accompanied by increased physical intensities in themovements of the heart muscles and valves (FIG. 15 b). However,comparison of the pre- and post-exercise synchronized BCG signals showthat the H-I-J-K-L-K-M-N peaks in the pre-exercise

BCG signal pattern, the peaks between the H-1-J-K-L-K-M-N are flattenedout and that the demarcation between the peaks is significantlydiminished (FIG. 15 a). However, their post-exercise synchronized BCGsignal (FIG. 15 b) shows that a clearly distinguishable H-I-J-K patternwas temporarily reestablished, presumably for a brief period of time tosupply an increased supply of oxygen to the heart muscles. However, thepresence of this “normal-appearing” BCG pattern during the post-exerciseperiod suggests that this individual has the potential to restore hiscardiovascular system to approximate the Functioning of the individualtested in Example 2. So, although in this example, the individual's rawunconditioned pre- and post-exercise ECG and BCG signals appeared to benormal although with an elevated heart rate, the system and the softwareof the present invention provided the means for detecting physiologicalabnormalities associated with physical malfunctioning with one or moreof their heart valves, heart muscles and vascular system. Furthermore,it is within the scope of this invention to store such data produced byan individual during sampling periods over extended periods of time, sothat improvements in the individual's cardiovascular system's functionand capacity can be recorded and reported as part of treatment, therapy,exercise programs and the like.

EXAMPLE 4

FIGS. 16 a and 16 b show the raw, unconditioned ECG and BCG signalsproduced by an individual before and after stress induced by physicalexercise as described in Example 1. This individual is consideredat-risk based on the sporadic breakdown in their post-exercise ECGsignal (FIG. 16 b) in conjunction with the substantial decreases in theamplitudes of the BCG signals (FIG. 16 b). However, conditioning the ECGand BCG signals and synchronizing the BCG signal with the ECG signalshowed that, during the pre-exercise resting period, the magnitude ofthe BCG H-I-J-K-L-K-M-N peaks are even more diminished than was seenwith the unhealthy individual in Example 3 with only the H-I waveclearly identifiable (FIGS. 17 a and 17 c). Although the intensity ofthe BCG peaks increased post-stress (FIG. 17 b), the amplitudes of thepeaks within the wave pattern were approximately the same suggestingthat even under stress, the post-right-ventricular contraction movementsof the heart produce as much signal amplitude as do the septum recoil(i.e., the H-I wave) and flow of blood into the pulmonary and aorticarteries (i.e., J-K wave). In a healthy individual as exemplified inExample 2 (FIG. 13 b), the amplitudes of the H-I and J-K waves aretypically greater than subsequent L-M-N waves.

EXAMPLE 5

FIGS. 18 a, 18 b, and 18 c compare the conditioned synchronized pre-andpost exercise BCG signals from a healthy individual (FIG. 18 a is takenfrom FIG. 13 c), an unhealthy individual (FIG. 18 b is taken from FIG.15 c) and an at-risk individual (FIG. 18 c is taken from FIG. 17 c). Aspreviously discussed, the healthy individual's pre-and post-exercisesynchronized BCG wave patterns are identical (FIG. 18 a). The unhealthyindividual's pre-exercise BCG wave pattern (FIG. 18 b) has substantiallydiminished H, J, and L peaks accompanied by flattened and elongated H-Iand J-K waves (exemplified by H¹, I¹ and K¹) while after exercise, theamplitudes of the H, J, and L peaks increase considerably, the H-I andJ-K waves are more clearly defined, and the L-M-N waves appear(exemplified by H², I², J², K², L², M², N²). The at-risk individual'spre-exercise BCG wave pattern exemplified by H¹, I¹, and K¹ peaks (FIG.18 c) is similar to the unhealthy individual's pre-exercise BCG wave(FIG. 18 b). However, the at-risk individual's post-exercise BCG wavepattern exemplified by H², I², J², K², L², M², N² peaks (FIG. 18 c) isdifferent from the unhealthy individual's BCG wave pattern (FIG. 18 b)indicating that different components of the at-risk individual'scardiovascular system arc abnormal relative to the unhealthyindividual's system, both systems in comparison to the healthyindividual's system as exemplified by the post-exercise BCG wave patternin FIG. 18 a. Those skilled in these arts will understand that storingsuch data in a database for future reference to in comparison with latercollected ECG and BCG data with the exemplary systems of the presentinvention, will enable: (1) assessments of the improvements ordeterioration in an individual's cardiovascular system over a period oftime, and also, (2) comparisons of the responses of an individual'scardiovascular systems pre- and post-stress to a broad populationdatabase.

While this invention has been described with respect to the exemplaryembodiments, those skilled in these arts will understand how to modifyand adapt the systems, methods, algorithms and heuristic methodsdisclosed herein for monitoring the physiological condition ofcardiovascular systems and for detecting abnormalities and malfunctionstherein by conditioning and synchronizing exemplary ECG and BCG signalsfor other applications. For example, the system of the present inventionmay be additionally provided with an implantable device configured forinstallation within an individual's body and for receiving thereinelectrical signals derived from the conditioned and synchronized ECG-BCGsignal sets, and for transmitting the derived electrical signals to atarget site within the individual's body for affecting a physiologicalresponse therein. Furthermore, it is possible for those skilled in thesearts to adapt the systems, methods and algorithms disclosed herein formonitoring the physiological condition of other types of mammaliansystems wherein a plurality of detectable signals are generated wherebythe signals are acquired, processed, synchronized and retransmitted forstorage and/or reporting and/or for providing returning stimulatorysignals to the originating, mammalian systems. Examples of suchmodifications include providing alternative types of paired signals forcondition and synchronization as exemplified by signals quantifyinglevels of blood sugar paired with signals for example quantifying bloodoxygen levels or alternatively, insulin levels, or alternatively,electrical impulses transmitted by the peripheral nervous system pairedwith electrical impulses transmitted by the central nervous systems, orfurther alternatively, with signals generated by systemic antibodies tovarious and individual types of cancers paired with signals generated byselected systemic biochemical markers such as proteins, and the like.Therefore, it is to be understood that various alterations andmodifications can be made to the systems, methods and algorithmsdisclosed herein for monitoring the physiological condition anddetecting abnormalities therein, within the scope of this invention.

1. A system for monitoring an individual's physiological conditioncomprising: a first device for coupling to said individual, said firstdevice for detecting and transmitting an electrocardiograph signal ofsaid individual; a second device for coupling to said individual, saidsecond device for detecting and transmitting a ballistocardiographsignal of said individual; a computer including a microprocessor incommunication with said first device and said second device, saidcomputer for receiving said electrocardiograph signal and saidballistocardiograph signal, converting said electrocardiograph signalinto electrocardiograph data, converting said ballistocardiograph signalinto ballistocardiograph data and synchronizing said electrocardiographdata with said ballistocardiograph data, said computer generating anoutput indicative of said individual's physiological condition.
 2. Thesystem according to claim 1, wherein said electrocardiograph signal andsaid ballistocardiograph signal are converted by an analog-digitalconverter.
 3. The system according to claim 1, wherein said first devicecomprises an electrocardiograph.
 4. The system according to claim 1,wherein said second device comprises an accelerometer.
 5. The systemaccording to claim 4, wherein the accelerometer is configured to bepositioned on the sternum of said individual.
 6. The system according toclaim 1, wherein said computer includes a database in communication withsaid microprocessor, said database for storing said electrocardiographdata and said ballistocardiograph data,
 7. The system according to claim1, wherein synchronizing said electrocardiograph data with saidballistocardiograph data includes aligning an R peak of anelectrocardiograph waveform corresponding to said electrocardiographdata with an H peak of a ballistocardiograph waveform corresponding tosaid ballistocardiograph data.
 8. The system according to claim 1,wherein said output is provided on a device selected from he groupconsisting of monitors, screens, printers and plotters.
 9. The systemaccording to claim 1, wherein said output comprises a synchronizedelectrocardiograph-ballistocardiograph waveform.
 10. The systemaccording to claim 6, wherein said output comprises a comparison of saidelectrocardiograph data and said ballistocardiograph data of saidindividual with reference electrocardiograph and ballistocardiographwave pattern data, said reference electrocardiograph andballistocardiograph wave pattern data being stored in said database. 11.The system according to claim 1, wherein said output comprises acomparison of at least one resting-stageelectrocardiograph-ballistocardiograph signal set and at least onepost-exercise electrocardiograph-ballistocardiograph signal set.
 12. Thesystem according to claim 6, wherein said computer includes a graphicaluser interface in communication with said microprocessor, said graphicaluser interface for allowing an operator to input data into saiddatabase.
 13. The system according to claim 1, further comprising one ormore filters for conditioning at least one of said electrocardiographsignal and said ballistocardiograph
 14. The system according to claim13, wherein said filters comprise a filter having high-pass cutofffrequency of about 40 Hz and a low pass filter of about 1 Hz forconditioning said electrocardiograph signal.
 15. The system according toclaim 13, wherein said filters comprise a filter having high-pass cutofffrequency of about 25 Hz and a low pass filter of about 1 Hz forconditioning said ballistocardiograph signal.
 16. A system formonitoring an individual's physiological condition comprising: a firstdevice for detecting and transmitting electrocardiograph signals of saidindividual; a second device for detecting and transmittingballistocardiograph signals of said individual; a third device incommunication with said first device and said second device forconverting said electrocardiograph signals into electrocardiograph dataand for converting said ballistocardiograph signals intoballistocardiograph data; a microprocessor in communication with saidthird device for receiving said electrocardiograph data and saidballistocardiograph data, synchronizing said electrocardiograph datawith said ballistocardiograph data, and generating an output indicativeof said individual's physiological condition.
 17. The system accordingto claim 16, wherein said third device comprises an analog-digitalconverter.
 18. The system according to claim 16, wherein said firstdevice comprises an electrocardiograph.
 19. The system according toclaim 16, wherein said second device comprises an accelerometer.
 20. Thesystem according to claim 19, wherein the accelerometer is configured tobe positioned on the sternum of said individual.
 21. The systemaccording to claim 16, further comprising a database in communicationwith said microprocessor, said database for storing saidelectrocardiograph data and said ballistocardiograph data.
 22. Thesystem according to claim 16, wherein synchronizing saidelectrocardiograph data with said ballistocardiograph data includesaligning an R peak of an electrocardiograph waveform corresponding tosaid electrocardiograph data with an H peak of a ballistocardiographwaveform corresponding to said ballistocardiograph data.
 23. The systemaccording to claim 16, wherein said output is provided on a deviceselected from the group consisting of monitors, screens, printers andplotters.
 24. The system according to claim 16, wherein said outputcomprises a synchronized electrocardiograph-ballistocardiographwaveform.
 25. The system according to claim 21, wherein said outputcomprises a comparison of said electrocardiograph data and saidballistocardiograph data of said individual with referenceelectrocardiograph and ballistocardiograph wave pattern data, saidreference electrocardiograph and ballistocardiograph wave pattern databeing stored in said database.
 26. The system according to claim 16,wherein said output comprises a comparison of at least one resting-stageelectrocardiograph-ballistocardiograph signal set and at least onepost-exercise electrocardiograph-ballistocardiograph signal set.
 27. Thesystem according to claim 21, further comprising a graphical userinterface in communication with said microprocessor, said graphical userinterface for allowing an operator to input data into said database. 28.The system according to claim 16, further comprising one or more filtersfor conditioning said electrocardiograph signals and/or saidballistocardiograph signals.
 29. The system according to claim 28,wherein said filters comprise a filter having a high-pass cutofffrequency of about 40 Hz and a low pass filter of about 1 Hz forconditioning said electrocardiograph signals.
 30. The system accordingto claim 28, wherein said filters comprise a filter having a high-passcutoff frequency of about 25 Hz and a low pass filter of about 1 Hz forconditioning said ballistocardiograph signal.